Game's save data file can be found in your device ( search Ixalon ) I haven't tried it with Eternum but did it with several other games , uninstalled the game but the save files seem to be secured in the device and whenever we download the game again , we can continue from where we left off ( and I dunno for any ongoing games I tried it for finished games )
I think you better get another copy of save data ( better not take any risks )
I think you're playing from android not on pc. Go to files and search Ixalon. then there will be a file called ... (like described on the screenshot) then head to the file ''game'' . That's where the file will be. Then search up for archive.rpa ( I'm seeing is a zip file in the 0.8 update so in there , there should be a file called archive.rpa or multiple files ) drag them into that file and you should be good to go.
I don't know this will surely works but I'm telling from the things I've done before :)
